The effect of ultrasonic vibrations on residual stresses and material properties of steel tubes during the cold tube drawing process

In this study, the ultrasonically assisted plug vibrating tube drawing system was developed for an industrial draw bench and investigated using experimental and finite element (FE) modelling. The effect of ultrasonic vibrations on the induced residual stresses on the drawn steel tubes is evaluated using the mechanical and X-ray diffraction (×RD) method. The results indicate that the distribution of induced residual stresses mostly shows compressive stresses under ultrasonic vibrations. In contrast, the residual stresses are tensile in nature for conventionally drawn tubes, which are not very desirable. The experimental results show 11% reduction in draw load, while the FE analysis shows a 13% reduction in draw load, which indicates that the experimental and FE results are in good agreement. In addition, the effect of ultrasonic vibrations on the tensile strength, yield strength and percentage elongation is investigated and compared with samples from conventionally drawn tubes. The ultrasonic-assisted tube drawing has resulted in favourable tensile properties, which helps in improving the formability limit of the tubes. The Von Miss stress distribution obtained indicates that the ultrasonically assisted drawing results in a more uniform and lower Von Mises stress when compared to conventionally drawn tubes.